With the advent of the communications era, one of the major markets for optical devices is portable electronics equipment, such as cellular telephone, pagers, two-way radios, data banks, computers and the like. Generally, it is desirable that the optical source devices in this type of equipment are compact with low power, inexpensive and include high quality optics. Through the use of digital signals which are being transmitted at ever increasing bandwidths, it is possible to transmit increasingly larger and more complex messages to remote portable units. In some instances it is possible to send complete messages, including alpha-numerics and/or graphics by way of novel pagers. Thus, complete messages can be sent to specific recipients by way of a pager, for example.
Also, in many instances it is desirable to provide a visual display on the communication transceiver to supply the operator with an indication of messages received, numbers actually dialed, and other minor but critical information. The problem is that the visual displays on prior art portable electronics equipment are extremely limited in size and require relatively high electrical power as well as a great amount of area to be sufficiently large to produce a useful display. Thus, while the present visual displays are generally sufficient for displaying the minor information, they are not capable of displaying large alpha-numeric and/or graphic messages.
The system that is normally used at the present time is one using a large image source and either a direct view image or low magnification optics. The major problem with this system is that it greatly limits the size of the portable electronics on which it is used. Basically, the image must be large enough for an operator to read and/or understand the information being displayed. Thus, for example, if one wanted to display an 8.5" by 11" sheet of paper (a standard letter), the direct view display must be 8.5" by 11" to be easily read. Such a display is clearly too large to be incorporated into most portable communications devices, such as pagers, two-way radios, cellular phones and the like.
In the prior art, for example, it is common to provide visual displays utilizing liquid crystal displays, directly viewed light emitting devices, etc. These produce very large and cumbersome displays that greatly increase the size of the transceiver and require relatively large amounts of power. Further, such displays, when used on pagers, greatly limit the amount and, in many instances, the type of messages that can be received.
Some types of devices have been proposed which are capable of displaying larger messages while utilizing a smaller amount of space in the portable electronic device. In one instance, the prior art includes a scanning mirror to produce a visual display but again this requires relatively large amounts of power and is very complicated and sensitive to shock. Also, the scanning mirror causes vibration in the unit that substantially reduces visual comfort and acceptability.
Some attempts have been made to produce displays using arrays of light emitting devices on a single semiconductor chip. Generally, a semiconductor chip, or integrated circuit, is mounted on a printed circuit board or the like and the accepted method for connecting the chip to external circuits is to use standard wire bond technology. However, when a semiconductor chip having a relatively large array of electrical components or devices formed thereon is to be connected, standard wire bond techniques can become very difficult. For example, if a relatively large array (greater than, for example, 10,000 or 100.times.100) of light emitting devices is formed on a semiconductor chip with a pitch (center-to-center separation) of P, then bond pads on the perimeter of the semiconductor chip will have a 2P pitch. This is true because every other row and every other column goes to an opposite edge of the perimeter to increase the distance between bond pads as much as possible.
At the present time, wire bond interconnects from bond pads having a pitch of 4.8 milli-inches is the best that is feasible. Thus, in the array mentioned above of 100.times.100 light emitting devices, the bond pads on the perimeter of the semiconductor chip would have a minimum pitch of 4.8 milli-inches, with 50 bond pads situated along each edge of the perimeter. As more devices are included in the array, more bond pads are required and the perimeter size to accommodate the additional bond pads increases at an even greater rate. That is, since the minimum pitch of the bond pads is 4.8 milli-inches, the pitch of the devices in the array can be as large as 2.4 milli-inches, or approximately 61 microns, without effecting the size of the chip. Thus, even if the devices can be fabricated smaller than 61 microns, the minimum pitch of the bonding pads will not allow the perimeter of the chip to be made any smaller. It can quickly be seen that the size of the semiconductor chip is severely limited by the limitations of the wire bonding technology.
Thus, there is a need for an improved dual image manifestation apparatus, interconnect and packaging structures and techniques which can substantially reduce limitations on the size of the image manifestation apparatus and the semiconductor chips used therein. In addition, there is a need for a portable communications device which will allow the user to view a transmitted display in either a quasi-direct view display mode or in a virtual image display mode.
Accordingly, it is a purpose of the present invention to provide new and improved dual image manifestation apparatus with an integrated electro-optic package.
It is another purpose of the present invention to provide a new and improved dual image manifestation apparatus with an integrated electro-optic package in which the apparatus is operational in either a quasi-direct view display mode or in a virtual image display mode by simply aligning the appropriate optical magnifying system.
It is a further purpose of the present invention to provide a new and improved dual image manifestation apparatus with an integrated electro-optic package which is compactly packaged and operational by the user in either a quasi-direct view display mode or a virtual display mode.
It is yet another purpose of the present invention to provide a new and improved dual image manifestation apparatus with an integrated electro-optic package including a quasi-direct view display mode and a large virtual display mode which is relatively easy and inexpensive to fabricate.
It is still another purpose of the present invention to provide new and improved dual image manifestation apparatus operational by the user to receive either a quasi-direct view display or a large virtual display which is fabricated in a single integrated electro-optic package which can be easily incorporated into portable electronic equipment.
It is another purpose of the present invention to provide new and improved communication transceivers with dual image manifestation apparatus and adjustable optic elements allowing the user to view the transmitted image in either a quasi-direct view display mode or a large virtual display mode.